Q 01/05

Where can a virus replicate?

A) Only inside a living cell

B) Only in animal blood

C) Anywhere warm and moist

D) In soil and water

Answer · why

A) Only inside a living cell

Viruses have no metabolism of their own, so they hijack a host cell's machinery to build copies.

Q 02/05

What is the study of viruses called?

A) Bacteriology

B) Parasitology

C) Epidemiology

D) Virology

Answer · why

D) Virology

It is a subspeciality of microbiology, dating from Beijerinck's work in the 1890s.

Q 03/05

What is a single virus particle outside a cell called?

A) A capsomere

B) A prion

C) A viroid

D) A virion

Answer · why

D) A virion

The term dates from 1959 and describes the released particle capable of infecting another cell.

Q 04/05

What is the protein coat that surrounds a virus's genetic material called?

A) The nucleoid

B) The envelope

C) The capsid

D) The membrane

Answer · why

C) The capsid

It is built from repeating protein subunits called capsomeres; some viruses add an outer envelope of lipids.

Q 05/05

Which plant pathogen, found in filtered sap in the 1890s, was the first of its kind ever described?

A) Influenza virus

B) Tobacco mosaic virus

C) Smallpox virus

D) Rabies virus

Answer · why

B) Tobacco mosaic virus

Dmitri Ivanovsky showed that sap from diseased plants stayed infectious after passing through a filter fine enough to trap bacteria.